In the event of a collision between two rail vehicles, a large part of the collision energy occurring is advantageously absorbed by plastic deformation in crumple zones that are deformable in a defined manner in the end areas of the rail vehicles. The crumple zones can be implemented as extensive crash areas or as crash elements with specific geometry and either incorporated in the supporting structure or mounted on the front structure as freestanding crash modules. However, especially with freestanding elements it must be taken into account that, in such elements, shear forces and bending moments of the kind occurring in the event of eccentric load application can produce global buckling with reduced energy absorption and consequently ‘riding up’ of the collision partners.
In order to counteract these problems, guides can be provided, for example, for absorbing shear forces and bending moments. U.S. Pat. No. 6,158,356 describes such a solution in which, in the front area of a rail vehicle, a front and a rear flat ring are disposed parallel to one another and perpendicular to the direction of travel. The rings are connected on their upper side by an articulated joint so that they rotate in the event of a crash, and each have on their underside two tubular damping elements which slide into one another. The disadvantage of this solution is not only the large space requirement and complex design, but also the fact that only a reduced compression distance is available for energy dissipation. Consequently, the rail vehicle can be damaged by transmission of impact energy.
Other solutions make use of the progressive plastic buckling behavior of axially compressed crash elements for energy dissipation in collisions. However, in the case of small cross-sectional dimensions and the absence of lateral guidance, these elements react sensitively to eccentric load applications. Such solutions are therefore unsuitable for overly large offset between the collision partners, as they cannot prevent twisting of the contact surfaces and ‘riding up’ of the collision partners can therefore occur.